The invention is related to the prior tool developments of DAVID H. SWALLOW, Pat. No. 4,488,515, dated Dec. 18, 1984. The invention comprises substantial improvements thereover, wherein the choke, the reamer, locking mechanism, packing components and criticality of materials therefor are highlighted. It is specifically useful as a combination boiler tool in isolating, testing by slow drain and repairing. It isolates only one safety control at a time. Within the device described hereinafter the choke comprising an expandable-contractable element being subject to recall, after having been compressed for long periods of time, includes an associated adjusting nut which may be spun back considerably more than was heretofore possible. By applying pressure between the invention compression rod knob of the hydraulic column choke and its compression rod sleeve knob, the rubber compression component thereof may accordingly be extended in length. The net effect will be to reduce the outer diameter of the rubber component less than its original or normal diameter, thereby entirely eliminating the possibility that a major portion of the expandible choke will remain expanded and thus become stuck inside the boiler or column piping. Likewise, this first improvement provides a better water seal in place, as the expandible choke component can not pull away from the end of its compression rod sleeve and return cone, if the associated take-up nut be accidentally unscrewed too far as it could in the invention of Pat. No. 4,488,515.
The new packing compression ring of the improved invention moreover now effectively contains a substantial part of the unit's locking mechanism. Thus, the improved locking mechanism now permits locking of its compression rod sleeve at any given point along the length thereof. In the invention of Pat. No. 4,488,515 this distance was heretofore limited to the length of extension bolts which were welded on each side of the unit's main housing. A new safety lock collar herein, likewise provides a positioning screw to prevent the collar from rotating on the safety lock when setting the locking screw. This, then prevents accidental screwing of the locking screw into one of the three slots which are cut parallel to the axis of the screw into the outer end of the safety lock, the purpose of the newly formed slots being to allow the outer end of the safety lock to move inward, compressing against the compression rod sleeve, thereby creating a locking effect when its setscrew may be securely screwed in tight. Not only does the improved locking mechanism greatly simplify the use of the tool and establish speed in locking same, it also eliminates the use of extraneous flat plates, locking nuts, etc., which heretofore required extra time in threading on and off, the socket, t-wrench and long threaded extensions. The new apparatus furthermore permits locking at any predetermined position in which the compression rod sleeve or reamer rod may be set; likewise it is common to either hereinafter defined ISO-TEST/choke or PRO-CHECK/reamer units.
Further advantages through improvements to the reamer may be stated as follows. In the improvement, both reamer and its return cone are unitary in construction. Extensions have been added to the rods permit use of the assembled unit in areas wherein space may be restricted, as for example underneath a boiler's breaching or by reason of related equipment restricting the available working space available. These rods and their extensions are disposed in sealed relation to a main body common, hereinafter described. In this first improvement, a new locking mechanism permits locking the reamer shaft/rod in position when adding or removing such an extension. Thus, if there is pressure inside the vessel or piping, it could otherwise rapidly force the length of working rod that may already be set inside the piping outward.
A second improvement to the basic concept comprises a given boiler with burner control protection against a low water condition, while the water column may be isolated from the boilers. This is especially useful in single control boilers, where no back-up protection may be available. Thus with the addition of an electric probe to the head of one invention test tool, used in the upper water column leg on hotwater heating boilers, this control will serve not only as the primary control when in use on single control boilers, but also as a secondary control on dual control boilers. This way a given boiler will always be protected, if the device of the second improvement is used properly. This second improvement applies only to the unit which is set into the upper leg on a given water column. The lower leg may still use the regular improved unit tool. The electric circuit herein may be tied into the conventional low water cut-off circuit by incorporating therein a normally closed lock out switch for this function. When the improved probe control circuits are plugged in, the normal circuit is thereafter opened, current then flowing through the present additional control circuit and back into the conventional circuit to the burner. This method places all the low water controls in series and thus any single control can shut down the burner.